How does gene therapy affect a cell? a. cells with defective genes are replaced with cells of normal genes. b. cells with normal genes are replaced with cells of defective genes. c. cells with abnormal genes are replaced with cells of destructive genes. d. cells with functioning genes are replaced with mutated genes.

Look at the images of different rocks. which rocks have a fine-grained texture? check all that apply. 1 2 3 4 5

2. how does the miller-urey experiment fall short of demonstrating that life can arise from inorganic molecules? explain. a. it doesn't show a leap between a collection of amino acids and a single-celled organism. b. it recreates the conditions that existed at the earth's beginning, but no molecules form as a result. c. it doesn't provide evidence of the formation of amino acids. d. it doesn't show how multicellular organisms developed from unicellular organisms

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?